The study of the mechanism of activation of adenylate cyclase by fluoride or hormones is being continued and a special new effort is being made to purify the enzyme. The delineation of binding sites for the substrated of phosphoglucomutase is being continued through the use of phosphorylated and nonphosphorylated sugars. A radioimmunoassay method for measuring the tuftsin tetrapeptide Thr-Lys-Pro-Arg is in the process of development. Work on the determinants of cell recognition will continue.